Gas turbine combustors are typically provided with floating collar or seal assemblies for mounting igniters or fuel nozzles to the combustor, in order to facilitate relative movement of igniters or fuel nozzles with controlled leakage therebetween during engine operation. This arrangement helps to avoid loading on the igniter or fuel nozzles from the combustor movement. Conventional combustor floating collar assemblies are provided with anti-rotation tabs or brackets to prevent the igniters or fuel nozzles from rotation, while permitting axial and radial/lateral movement with respect to the combustor. Fretting wear of the anti-rotation tabs or brackets occurs in conventional floating collar assemblies due to aerodynamic loading and vibration. This can result in pre-mature removal of engines in the field due to difficulties reinstalling igniters or fuel nozzles during overhaul. A floating collar with worn-out anti-rotation tabs may start rotating and creating grooves in the igniter or fuel nozzle which is secured by the floating collar. Accordingly there is a need to provide a solution which addresses these and other limitations of the conventional floating collar assemblies.